This invention relates to a folding knife and, more particularly, to a locking mechanism for a folding knife.
Locking mechanisms for knife blades have been around almost as long as knives themselves. Most use a spring element, or spring biased element, moving in the plane of the knife as a locking element. Hallverson, U.S. Pat. No. 1,365,487, and Guttzeit, U.S. Pat. No. 1,734,126, are examples.
Another type of known locking mechanism moves laterally to the plane of the knife. Examples include: McLay, U.S. Pat. No. 1,521,778; Walker, U.S. Pat. No. 4,896,424; and Chen, U.S. Pat. No. 5,699,615. McLay provides a three-piece side panel, one piece of which is a spring-biased lever having a locking flange at one end. The flange is moved into and out of apertures in the tang of the blade to effect locking. Such movement is produced by a plate on the opposite end of the lever. Inadvertent squeezing of the plate could cause closure of the blade, perhaps on the fingers of the user. Walker and Chen both provide a deflectable spring lock internally of the knife handle. Both also require an extra element for the locking mechanism in addition to their side panels. And, in each, the tip of the spring coacts directly with the blade to effect locking.
It is a primary object of the present invention to provide a blade lock for a folding knife that is easy and safe to use.
It is another object of the present invention to provide a blade lock for a folding knife which securely locks the knife blade in an open position even as the blade lock wears from use.
It is another object of the present invention to provide a blade lock having replaceable parts, thereby further prolonging the useful life of the folding knife.
It is another object of the present invention to provide a blade lock for a folding knife that is simple and economical to manufacture.
These and other objects are achieved in accordance with one aspect of the present invention by providing a blade lock for a folding knife wherein the spring which biases the lock into locking engagement with the blade is a part of one of the side panels of the folding knife.
In accordance with another aspect of the present invention, there is provided a blade lock for a folding knife wherein the locking element is replaceably mounted on the free end of the spring.
In accordance with another aspect of the present invention, there is provided a blade lock for a folding knife wherein the locking element is more wear-resistant than the side panels, substantially reducing the production costs of the knife.
Finally, in accordance with a more specific aspect of the present invention, there is provided a blade lock for a folding knife wherein the locking element comprises a disc coacting with a conical recess provided in the end face of the blade, so that as the disc wears, it will maintain an efficacious lock merely by seating deeper into the recess.